MXene-based composite double-network multifunctional hydrogels as highly sensitive strain sensors

Abstract

Flexible sensors have attracted extensive attention due to their good wearable performance and high accuracy in acquiring external information. Herein, a highly stretchable, good stability, and functionally diverse MXene composite double-network hydrogel is fabricated by incorporating conductive MXene nanosheets into a polyacrylamide (PAM) and sodium alginate (SA) hydrogel network. Hydrophilic MXene nanosheets are uniformly distributed throughout the hydrogel, forming a 3D conductive network, which makes the hydrogel conductive and highly sensitive. Meanwhile, the existence of supramolecular interactions between MXene and the PAM/SA double-network hydrogel matrix resulted in a great improvement in the mechanical properties of these hydrogels. The MXene nanocomposite hydrogel prepared by this method has good tensile properties (2000%) and excellent stability. This hydrogel can be assembled into flexible sensors for dynamically monitoring human movements, such as joint bending, throat vocalization and facial expression changes, and can perform handwriting recognition and human–computer interaction. This work paves the way for potential application of flexible strain sensors in personalized medical monitoring and human–computer interaction.